1. Field of the Preferred Embodiment(s)
This invention generally relates to position sensing and to a position sensor which is compact, durable and precise. More specifically, the invention relates to a noncontacting low profile position sensor.
2. Description of the Related Art
Position sensing is used to allow an electrical circuit to gain information about an event or a continuously varying condition. There are a variety of known techniques for angular position sensing. For example, optical, electrical, electrostatic, and magnetic fields are all used in a sensor to measure position. There are many known sensors such as resistive contacting networks, inductively coupled ratio sensors, variable reluctance devices, capacitively coupled ratio detectors, optical detectors using the Faraday effect, photo-activated ratio detectors, and electrostatic ratio detectors.
There are many applications for sensors, and a wide variety of technologies to fill these needs. Each of these technologies offers a unique set of advantages and limitations. limitations. Of these technologies, magnetic sensing is known to have a unique combination of long life components and excellent resistance to contaminants.
Regardless of the arrangement and method for changing the field about the sensor, the magnetic circuit faces several obstacles which have not been overcome. Movement of the sensor relative to the gap as a result of bearing play will lead to a variation in field strength measured by the sensor. This effect is particularly pronounced in Hall effect, magneto-resistive and other similar sensors, where the sensor is sensitive about a single axis and insensitive to perpendicular magnetic fields.